Door Bottom Repair

[Creeker]

Hey y'all. I'm new to body work, and I'm not sure how much I can tackle. (I've done a lot of woodwork, but not much metal). My knottiest problem right now is with door bottom rust. I tried a search for this, but I must not be using the right terms; I'm not finding much.

Can someone advise me on

1. What's a good/easy way to arrest the rust at the door bottoms? Use whatever rust products suggested elsewhere in the forum?
2. I assume cut-out and weld new is the only real solution to the problem. Is this a $$$$$ repair for a body shop?
3. Or is grinding/bondo a possibility? That I could do myself.
4. What to do about new gutters in this seam?

Thanks.

 

[Nomis]

Door bottom patch panels are available, and probably the best way to go if you have rust to the point where holes have formed. I will be going this route when I repair mine, down the line.
If you go with a body shop / weldor - It will probably not be inexpensive